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Power consumption


    I want to calculate the power consumption of the following components to ensure that my design doesn't crosses certain power limit so kindly help me out with the necessary details as I am little confused with the datasheet values.

1. AD8145YCPZ-R7

2. AD8146ACPZ-R2

3. ADA4412-3ARQZ

4. AD8062ARZ

5. AD725ARZ

6. EL1881CSZ

A) I want supply voltage and supply current values to calculate power.

B) Kindly provide me typical values which can help me reduce power consumption of my system.

C) Also tell me if there is any necessity to use negative voltage or dual supply and risks involved if only positive voltage is used.

D) Provide me a solution about voltage supplies to enhance the overall performance of these components.

Parents on Sep 25, 2018 11:26 AM in reply to vishwajit.vk

A) & B) Power supply requirements are based on system implementation.  The data sheets contain all the current information needed to calculate complete system power requirements.  Regarding the AD8145, the data sheet shows the quiescent power requirements however you must also include the output load requirements.

As a simple example: Assume the ADV8145 is being supplied by +-5V, the load is 100 Ohms and the input is 1Vrms sinewave.

So P5Vquiescent = 5V * 70mA = 350mW

P-5Vquiescent = -5V * -65mA = 325 mW.

P5Vload = P-5VLoad = 100 * 1/QRT(2) / 2 = 35mW

Pad8145_5V = P5Vquiescent + P5Vload = 350mW + 35mW = 385mW

Padad8145-5V = P-5Vquiescent + P-5Vload = 325mW + 35mW + 360mW

The same basic approach applies to all the other devices you've listed.  I would pencil sketch a system, then build a simple excel spread sheet that can quickly calculate you power needs.

C) Split power rails are useful if the source singles are close to ground which often is the case.  Single rails can be done but more care has to be taken with AC couplings and signal processing.

D) A solution is dependent on what your system looks like.   To save power you can disable parts when the signal path is not used.

  • if my supply voltage is 5 V, Load = 100 Ohm,  1Vrms-sinewave

    Then , Power Consumption due to Load = ((Vrms)^2)/R) =(1/100)= 10mW

    Could you please explain how you got P5Vload = P-5VLoad = 100 * 1/QRT(2) / 2 = 35mW ?

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